Pressure Container for a Transport Container Arrangement

ABSTRACT

The present invention concerns a pressure container ( 1 ) with a jacket comprising partial cylindrical jacket shells ( 2, 4 ) that are located parallel next to each other and define a bead ( 8, 10 ) in the longitudinal direction. The end faces thereof are closed off by a curved bottom ( 16, 18 ), wherein between the partial cylindrical shells ( 2, 4 ) a tractive element designed in particular as a flat wall ( 6; 6   a   , 6   b ) is arranged, the upper or lower edge ( 12, 14 ) of which extends into or penetrates the upper or lower bead region ( 8, 10 ). There is furthermore provided a shell element ( 42 ) running in the longitudinal direction and connecting the jacket shells ( 2, 4 ) and the tractive element ( 6 ), being firmly connected at least in sections to the jacket shells ( 2, 4 ) and to the particularly beveled edge ( 12, 12   a   ; 14, 14   a ) of the tractive element ( 6 ), so that a girder structure is formed in the bead region ( 8, 10 ). The invention further relates to a transport container arrangement, particularly a tank container unit ( 100 ) having a pressure container ( 1 ) according to the invention.

The present invention concerns a pressure container with a jacket comprising partial cylindrical jacket shells that are located parallel next to each other and define a bead in the longitudinal direction, whose end faces are closed off by a curved bottom. Pressure containers with partially cylindrical jacket shells whose cross section resembles an octagon are known, for example, from DE-A-36 06 247, DE-A-31 25 963, DE-A-29 51 554 and EP 1067326 B1. Such pressure containers are especially suitable as transport container for road vehicles, such as tank semitrailers, or for tank container arrangements that require containers which should make especially effective use of a structural space with reduced height and ensure high compressive strength at the same time as a weight-economizing use of material.

The best compressive strength is afforded by a circular cylindrical cross section, although this makes inadequate use of a rectangular cross section of the structural space with long sides situated horizontally. Such a cross section of the structural space with reduced height is also filled up with several pressure-tight full cylindrical containers alongside each other (FIG. 10). Considerable loss of space also still occur with such an arrangement. Box-shaped, elliptical (FIG. 11) or oval cross sections (FIG. 12) do not afford the required compressive strength.

Therefore, pressure containers according to the preamble of claim 1 have been developed. These afford substantial advantages in regard to space utilization over full cylindrical pressure containers and are superior in pressure engineering to box-shaped or oval tank cross sections that are used in particular for petroleum products; however, they have worse utilization of space. Especially for long pressure containers it is helpful and sometimes also required to provide tractive elements between the partially cylindrical shells to join the beads together in terms of pressure engineering. In this case, a tractive element in the shape of a flat wall that projects into or passes through the upper or lower bead region is especially easy to fabricate (see, e.g., EP 1067 326 B1). The partially cylindrical shells are then placed against this wall, abutting with each other, and joined or welded to it.

The problem is to further improve such pressure containers with a jacket of partially cylindrical jacket shells in terms of their space utilization and/or compressive strength.

This problem is solved by a pressure container according to claim 1, in which a shell element is provided that joins together the jacket shells and the tractive element. This shell element then closes the bead region—as a roof element on the top side and a floor element on the bottom side—and forms with these elements or the enclosed regions a profiled beam structure in the crotch region, which provides additional stabilizing action both against internal and external pressure loads, and against overturning loads.

For applications in which a double jacket is required, such as for containers designed for storage of hazardous goods, without having special structural features such as catching troughs, the arrangement of claim 2 is used.

The shape stability of the shell element is further enhanced by cambers (meaning here a cylindrical/prismatic camber about a lengthwise axis) or edges (claim 3).

Claim 4 specifies closing the region resulting from the different opening contours of the cambered floor and the jacket (the jacket shells) with a flat spandrel element running perpendicular to the lengthwise axis of the tank.

A further stabilization occurs if the spandrel elements are also each joined to the end faces of the tractive element, according to claim 5.

The present invention concerns a pressure container with a jacket comprising partial cylindrical jacket shells that are located parallel next to each other and define a bead in the longitudinal direction, whose end faces are closed off by a curved bottom. Pressure containers with partially cylindrical jacket shells whose cross section resembles an octagon are known, for example, from DE-A-36 06 247, DE-A-31 25 963, DE-A-29 51 554 and EP-A 1 326. Such pressure containers are especially suitable as transport container for road vehicles, such as tank semitrailers, or for tank container arrangements that require containers which should make especially effective use of a structural space with reduced height and ensure high compressive strength at the same time as a weight-economizing use of material.

The best compressive strength is afforded by a circular cylindrical cross section, although this makes inadequate use of a rectangular cross section of the structural space with long sides situated horizontally. Such a cross section of the structural space with reduced height is also filled up with several pressure-tight full cylindrical containers alongside each other (FIG. 10). Considerable loss of space also still occur with such an arrangement. Box-shaped, elliptical (FIG. 11) or oval cross sections (FIG. 12) do not afford the required compressive strength.

Therefore, pressure containers according to the preamble of claim 1 have been developed. These afford substantial advantages in regard to space utilization over full cylindrical pressure containers and are superior in pressure engineering to box-shaped or oval tank cross sections that are used in particular for petroleum products; however, they have worse utilization of space. Especially for long pressure containers it is helpful and sometimes also required to provide tractive elements between the partially cylindrical shells to join the beads together in terms of pressure engineering. In this case, a tractive element in the shape of a flat wall that projects into or passes through the upper or lower bead region is especially easy to fabricate. The partially cylindrical shells are then placed against this wall, abutting with each other, and joined or welded to it.

The problem is to further improve such pressure containers with a jacket of partially cylindrical jacket shells in terms of their space utilization and/or compressive strength.

This problem is solved by a pressure container according to claim 1, in which a shell element is provided that joins together the jacket shells and the tractive element. This shell element then closes the bead region—as a roof element on the top side and a floor element on the bottom side—and forms with these elements or the enclosed regions a profiled beam structure in the crotch region, which provides additional stabilizing action both against internal and external pressure loads, and against overturning loads.

For applications in which a double jacket is required, such as for containers designed for storage of hazardous goods, without having special structural features such as catching troughs, the arrangement of claim 2 is used.

The shape stability of the shell element is further enhanced by cambers (meaning here a cylindrical/prismatic camber about a lengthwise axis) or edges (claim 3).

Claim 4 specifies closing the region resulting from the different opening contours of the cambered floor and the jacket (the jacket shells) with a flat spandrel element running perpendicular to the lengthwise axis of the tank.

A further stabilization occurs if the spandrel elements are also each joined to the end faces of the tractive element, according to claim 5.

In terms or pressure engineering and fabrication engineering, a spandrel element according to claim 6 is advantageous; especially when an outer contour region follows the inner peripheral contour of the cambered bottom, that is, when it can be inserted into the latter, and has an inner contour region that projects inwardly into the interior of the container beyond the bead region, so that the peripheral contour at the end faces of the jacket shell always travels along the facing surface of the spandrel element. In this way, the jacket formed from the jacket shells can always be set cleanly by its end faces against the open end of the cambered bottoms, in which the corresponding spandrel elements are set flush with the edge, without this requiring additional fitting or notching work. The contour regions meet at an acute angle in the apex and base regions of the jacket shells and provide there an additional reinforcement advantageous to the pressure engineering, absorbing the peak stresses occurring there on account of the internal pressure of the container.

According to claim 7, the reinforcement is further improved and the peak stresses are further absorbed by providing riblike extensions at the ends of the spandrel element, which basically follow the common peripheral contour of bottom and jacket shell and go beyond the apex or base region where the peak stresses occur.

According to claim 8, the jacket shells have circumferential segments of different curvature. In particular, the curvatures in the upper and lower bead region are smaller—that is, with broader radius of curvature—than the curvatures of the circumferential segments that join the top apex to the bottom base region of the jacket shells and form the side waste regions of the container Thanks to this feature, the depth of the bead formed at the seam between the partial cylindrical jacket shells extending in the lengthwise direction can be reduced, thereby increasing the useful volume of the pressure container without substantially reducing the compressive strength. At the same time, it is easier to attach a curved bottom whose opening encompasses this smaller bead region, since the difference in cross section between the opening cross section of the bottom and that of the jacket is smaller.

In addition, the curvatures in the upper and lower bead region can also differ from each other. That is, the bead depth is different at the lower side of the container than at the upper side. A greater curvature—narrower radius—leads to a deeper bead and a smaller curvature—larger radius—to a shallower bead. A shallower bead in the lower region can be helpful, for example, for the emptying of the adjacent base regions of the individual jacket shells without any remainders. A deeper bead, on the other hand, confers a greater shape stability on such a pressure container in this region, so that it can be supported on beams running along the tank base—such as the lengthwise girders of a semitrailer, or the loading skids of a hook lift system.

According to claim 9, it is also possible to provide different wall thicknesses per section of the circumference.

Claim 10 concerns a transport container arrangement that is provided with a pressure container according to the invention.

Sample embodiments of the present invention are described hereafter by means of the drawings. There are shown:

FIG. 1, a perspective view of a pressure container according to the invention,

FIG. 2, a perspective cross sectional view (section A-A) of the pressure container depicted in FIG. 1,

FIG. 3, a perspective longitudinal section view (section B-B) of the pressure container depicted in FIG. 1,

FIG. 4, a perspective view of the pressure container from FIG. 1, in which one end bottom has been omitted,

FIG. 5, a perspective representation of the container depicted in FIG. 4, without the spandrel sheets,

FIG. 6, a perspective representation of a middle wall with inclined spandrel elements,

FIG. 7, a view of an alternative spandrel element in two alternative configurations,

FIG. 8, a schematic representation of two alternative cross section configurations of the cylindrical tank segment

FIG. 9, a tank container unit with a container according to the invention,

FIG. 10, a double cylindrical cross section of the prior art,

FIG. 11, an elliptical (left half) and a box-shaped (right half) cross section in the prior art, and

FIG. 12, an oval cross section of the prior art.

The pressure container 1 shown in FIGS. 1 to 5 comprises two partial cylindrical jacket shells 2, 4 which, as can be seen from FIGS. 2 and 5, are welded in the lengthwise direction to a tractive element fashioned as a flat wall 6. The flat wall 6 has the same length as the partial cylindrical jacket shells 2 and 4.

Each of the jacket shells 2, 4 has circumferential segments of different curvature 2 a, 2 b, 2 c and 4 a, 4 b, 4 c. The circumferential segments 2 a and 4 a run from the juncture with the flat wall 6 to the apex line 7 of the particular jacket shells 2 and 4. Starting from the apex lines, the circumferential segments 2 b and 4 b run to the lower base lines 9 of the jacket shells 2, 4, from which the circumferential segments 2 c and 4 c run to the flat wall 6. The circumferential segments 2 b and 4 b have a radius of curvature of 600-1300 mm in the waist region, while the upper and lower circumferential segments 2 a, 2 c and 4 a, 4 c have a radius of curvature of 600-3000 mm.

These radius ranges are indicated for tank containers or vehicles with a maximum width of 2600 mm. For other dimensions, correspondingly different radius ranges and relations can be indicated, being adapted to the actually existing outside dimensions of the tank containers or vehicles (train, truck).

The circumferential segments 2 a and 4 a form an upper bead region 8 and the circumferential segments 2 c and 4 c a lower bead region 10. The upper end 12 and the lower end 14 of the flat wall 6 project into the bead regions 8 and 10; the lower end 14 as far as the plane defined by the base lines 9 of the jacket shells 2 and 4 and the upper end 12 beyond the plane defined by the apex lines 7 of the jacket shells 2 and 4. Both ends 12 and 14 are provided with a beveling 12 a and 14 a for stabilization. The flat wall 6 is provided with a passage opening 50, reinforced with a collar 52.

The ends of the jacket shells 2 and 4 are closed with curved bottoms 16 and 18 (FIGS. 1 and 3), which in turn can be inserted into a container frame 22 by an attached end ring 20 (FIGS. 1 and 9).

In order to balance out and close the difference in cross section between the bead regions 8 and 10 and that of the oval bottom cross section, spandrel elements 24 and 26 are provided there, being arranged as flat metal sheets transversely to the longitudinal direction. In the sample embodiment depicted, the lower spandrel elements 26 are each provided with an outer contour region 28 (FIG. 4), which follows the straight inner circumferential contour segment of the curved bottom 16 and 18 and extends between the two base lines 9 of the partial cylindrical jacket shells 2 and 4. An inner contour region 30 extends inside the circumferential contours of the circumferential segments 2 c and 4 c that define the bead region 10. The outer contour region 28 and the inner contour regions 30 extend roughly at an acute angle relative to each other and meet in the ends 32 which lie in the area of the base regions (base lines 9).

At the upper spandrel element 24, the outer contour region 34 likewise follows the straight upper circumferential contour segment of the bottoms 16 and 18 and extends by its inner contour regions 36 to the ends 38, which like the lower spandrel elements 26 end in the apex regions (apex lines 7). While the lower spandrel element 26 is arranged entirely inside the bottom contour 1, the outer contour region 34 of the upper spandrel element 24 projects beyond the bottom contour and extends outside of it at roughly the same height as the beveling 12 a.

FIG. 6 shows a sample embodiment (tank shells 2, 4 not depicted) in which spandrel elements 24 a, 26 a are provided, which likewise extend transversely to the container but are inclined in the lengthwise direction. Such a configuration makes it possible to shorten the flat wall 6 serving as the tractive element in sections and thus save on material and weight. The outer contour region of the upper spandrel element 24 a protruding from the tank is beveled, and so is coupled (welded) to the beveling 12 a and to the end 12 of the flat wall 6.

Openings 40 are provided in the jacket shells 2 and 4, into which typical container ports such as manhole, filling ports, vent ports, and safety valve ports are inserted (see FIG. 4).

In the container apex an additional shell element 42 is provided, which is welded at least for sections to the jacket shells 2 and 4 at its side edges 44 in the apex regions and to the upper spandrel element 24 at its end faces 46. An edging 47 extends in the middle of the shell element 42, which comes to lie against the beveling 12 a and is fastened to this via plug welds 48. In this way, the circumferential segments 2 a, 4 a, the upper end 12 of the flat wall 6 with the beveling 12 a and the shell element 42 form a stabilizing longitudinal girder unit, which is closed at its ends by the upper spandrel elements 24 and thus further stabilized.

The jacket shells 2 and 4 in the sample embodiment depicted (FIGS. 1, 2 and 4) are encompassed by a double jacket 5, which ends in the upper region (roughly at maximum fill level) of the pressure container 1 and fully encloses the base regions 2 b, 4 c and thus also the lower bead region 10, likewise extending between the base lines 9. This double jacket 5 prevents product from escaping in event of damage to the jacket shells 2 and 4. It can be supplemented with additional outer bottoms (not shown), which then also form a double jacket in the area of the curved bottoms 16 and 18. In the lower region, the double jacket 5 can likewise be connected by plug welds to the beveling 14 a at the lower end 14 of the flat wall 6 for further stabilization. A similar fixation can also be done in the base regions by intermediate layers inserted there (e.g., double metal sheets) on the outside of the jacket shells 2 and 4, so that here as well a stabilizing girder element is realized in the lower bead region 10.

The double jacket 5 is left out in FIG. 5. In one configuration not shown, a flat, curved or beveled shell element can be arranged in the lower bead region 10, which then defines a similar girder structure to the upper shell element 42.

In the sample embodiment shown, the ends 32, 38 of the spandrel elements 24 and 26 extend in the base and apex regions of the jacket shells 2 and 4, which at the same time also form the transitions at which the straight circumferential segments of the bottoms 16 and 18 pass into the curved circumferential segments. This point is therefore especially critical in terms of pressure engineering. In order to further reduce the peak stresses occurring there, especially under internal pressure, a riblike prolongation 132 a, 132 b is shown in the sample embodiment of FIG. 7, which follow the common circumferential contour of bottoms 16, 18 and jacket shells 2, 4 and extend beyond the apex lines 7.

In configuration a (left), the spandrel element 24 is larger as a whole and projects by the region 132 a beyond the left apex line 7. In configuration b (right), only one cover strap 132 b is provided, which extends beyond the apex line 7.

FIG. 8 shows additional cross section variants in which the cylindrical jacket region encompassing the jacket shells 2, 4 and the flat wall 6 are made from one (configuration A) or two (configuration B) pieces, in which flat regions 6; 6 a, 6 b are edged against the curved jacket shells 2, 4, and the jacket ends are each welded to the edging lines 102, 104. The two-part configuration B consists of two shell elements 2, 4 each with one flat region 6 a, 6 b. In this design, the ends of the jacket shells are likewise welded to the edging lines 102, 104 and the flat regions 6 a, 6 b to each other in the lengthwise direction of the container.

There are also configurations (not shown) in which the jacket shells not only have independent radii of curvature, but also different wall thicknesses are provided for segments of the circumference. This can equalize the generally higher compressive stresses for the broader (larger) radii of curvature. This stress-optimized design enables further weight savings and higher compressive loads.

For those containers that are provided with a double jacket 5, this outer jacket 5 can also be used as an active structural element to absorb the compressive loads. This presupposes a force-transmitting coupling between inner container and outer container. This is accomplished, for example, by a supporting girder (not shown) provided between the inner and outer walls, enabling a pointlike or linear force transmission between the container walls. At especially vulnerable points, additional node sheets can also be provided for the coupling (not shown), which make possible an especially effective shifting of peak loads occurring on the inner wall to the outer wall.

FIG. 9 shows the pressure container 1 in a tank container unit 100 in which it is coupled to the latter by end rings 20. The tank container unit 100 represented is suitable for a hook lift and comprises load skids 101 and an equipment room 102, as well as a folding railing unit 103, so that the unit shown can be used as a largely self-sufficient supply unit.

Further variants and configurations of the present invention will be apparent from the claims to the person versed in the art. 

1. Pressure container with a jacket comprising partial cylindrical jacket shells that are located parallel next to each other and define a bead in the longitudinal direction, whose end faces are closed off by a curved bottom, and between the partial cylindrical shells a tractive element designed in particular as a flat wall is arranged, the upper or lower edge of which extends into or penetrates the upper or lower bead region (8, 10), characterized in that there is provided a shell element running in the longitudinal direction and connecting the jacket shells and the tractive element, being firmly connected at least in sections to the jacket shells and to the particularly beveled edge of the tractive element, so that a girder structure is formed in the bead region.
 2. Pressure container according to claim 1, in which the shell element is part of an outer jacket at least partially surrounding the jacket and tightly joined to this.
 3. Pressure container according to claim 1, in which the shell element has a camber or edge running in the lengthwise direction.
 4. Pressure container according to claim 2, in which an opening contour of the curved bottoms has a different course in the bead region than that of the jacket shells and the region so defined is closed by means of a flat spandrel element running perpendicular to the lengthwise axis of the tank.
 5. Pressure container according to claim 4, in which the spandrel element is firmly joined to one end face of the tractive element and the shell element.
 6. Pressure container according to claim 4, in which the spandrel element has an outer contour region, which follows the inner peripheral contour of the cambered bottom in the bead region, and an inner contour region that runs inside the peripheral contour of the jacket shell in the bead region, while the two contour regions meet at ends lying in the apex and base region and basically make an acute angle.
 7. Pressure container according to claim 4, in which the ends of the spandrel element have a riblike extension, which follow the common peripheral contour of bottom and jacket shell and go beyond the apex or base region.
 8. Pressure container according to claim 1, in which at least one jacket shell has circumferential segments of different curvature, in particular, one circumferential segment in the upper and lower bead region and one circumferential segment between an apex and a base region, while the circumferential segment between apex and base region is more curved than a circumferential segment in the upper and lower bead region and/or the circumferential segment in the upper bead region is more/less curved than that in the lower bead region.
 9. Pressure container according to claim 8, in which sections of the circumference are provided with different wall thicknesses.
 10. Transport container arrangement, particularly a tank container unit having a pressure container according to claim
 1. 11. Pressure container according to claim 3, in which an opening contour of the curved bottoms has a different course in the bead region than that of the jacket shells and the region so defined is closed by means of a flat spandrel element running perpendicular to the lengthwise axis of the tank.
 12. Pressure container according to claim 11, in which the spandrel element is firmly joined to one end face of the tractive element and the shell element.
 13. Pressure container according to claim 11, in which the spandrel element has an outer contour region, which follows the inner peripheral contour of the cambered bottom in the bead region, and an inner contour region that runs inside the peripheral contour of the jacket shell in the bead region, while the two contour regions meet at ends lying in the apex and base region and basically make an acute angle.
 14. Pressure container according to claim 11, in which the ends of the spandrel element have a riblike extension, which follow the common peripheral contour of bottom and jacket shell and go beyond the apex or base region. 